A 3D Magnesium MOF PCN-72 has been synthesized from the solvothermal reaction of Mg(NO3)2 and a linear ligand. This MOF has a unique structure with 1-dimensional (1D) channel as well as infinite metal chains, which resembles the topology of MIL-53. It is thermally and moisture stable. In situ powder X-ray diffraction studies reveal its interesting phase transitions under temperature change. Calculation shows that each phase of PCN-72 exhibits unique and unusual thermal expansion properties. After removing coordinated solvent at Mg chains, PCN-72 can selectively adsorb CO2 over N2.
